Your comment may have been supportive to the artist's feelings, but you really didn't provide any constructive criticism or make any effort to help them become a better artist. I think there is value in being real with people about what your opinion is. It's ok to say that you think some art is bad or they didn't try hard enough. It's like in school when everyone gets a "participant" ribbon. That's great for kids feelings, but it doesn't make anyone work to improve themselves. Many aspiring artists hit a brick wall of frustration because everyone is too generous with their compliments and when it comes time to sell the art...no one is buying and they are left scratching their heads. Finally someone comes along and has the balls to tell them that their art simply isn't good enough...and then gives them advice on what they can do better.

In my opinion, if you want positive feedback on everything you do, then you should ask your parents what they think. They'll almost always have something nice to say. But if you come to an art sub, you should expect the other artists to be more honest and provide constructive criticism so you become a better artist. No on is saying OP is a bad person, or should give-up art.

I don't reject abstract art on the idea that that's abstract. In fact I like a lot of abstract art. But some pieces look like they took about 15 minutes to make and don't really show much technique other than the artist swirling some paint on a canvas. I think when other artists support this low-effort art it only encourages people to make more bad art instead of working to refine their skills and techniques.